As a follow-up, it would be helpful if Epicor would update its existing install packages (even for older versions!) with the proper root cert, and also add a section in the documentation about how to configure Payflow in test mode… The “paypal_pfnvp_test” processor, and the “Test mode” checkbox are documented exactly nowhere (including the latest versions of the install PDF), the only reason I managed to find the answers is by shrewed googling for an hour. Not very efficient…
The documentation should also list the test mode card numbers and expected results while you are at it, or at the very least point to this URL somewhere in there: Test Payflow Transactions .